Bump nextra from 3.0.2 to 3.0.3

Bumps [nextra](https://github.com/shuding/nextra) from 3.0.2 to 3.0.3.
- [Release notes](https://github.com/shuding/nextra/releases)
- [Commits](https://github.com/shuding/nextra/compare/[email protected]@3.0.3)

---
updated-dependencies:
- dependency-name: nextra
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>